Has anyone ever used the dust and dirt on your car to leave a message? Watch this video from Brazil. The stencil they use reads, "Bike -- not as dirty." (via Copenhagenize.) Speaking of which, check out the Sierra Club's bike resource page here.

What's new news -- as if the ocean needs more problems -- is that acidification correlates with fish fatality, according to a study released last week.

Chemists out of Stony Brook University discovered that the survival of fish larvae drastically decreases as atmospheric carbon rises. A separate recent study found damaged and dead tissue in fish larvae caused by inflated carbon levels. Predictably, adult fish fared better in such scenarios, according to these studies. But the fact that fish can directly feel the brunt of the changing world -- something that wasn't considered before -- suggests that the weight human activity has placed on our oceans is more complicated than previously realized.

Because scientists used "near-future conditions" in their tests, the results indicate that "ocean acidification may be having an impact on these species today." But because some parts of the ocean, like coastal waters, seasonally experience "extremely acidified waters" more than other parts, scientists have yet to figure out how widespread this is. Fish already have to deal with over fishing, runaway plastic pollution, and mercury from coal power plants. Now they can add acid to the list.

If all of this is in the back of your mind, but you enjoy a plate of fish from time to time, take a look at the Monterey Bay Aquarium's Seafood Watch for recommendations on what to order at the restaurant and what to avoid. And for all you app-thusiastic sushi lovers out there, download the Sierra Club's free Safe Sushi app for your Android or Apple device.

Planet Forward's Susanna Murley recently offered five ideas for the electric car industry as it heads into 2012. Among them is the electric CityCar, developed at MIT -- a "radical redefinition" of urban transportation that would make parking much less of a chore. It's not Back to the Future, but it's still a pretty great video. And be sure to check out Susanna's other ideas here.

With the Obama administration and the Environmental Protection Agency issuing the first-ever nationwide protections on mercury that come from dirty coal-fired power plants, there is plenty to smile about. More than 300,000 American babies are born each year exposed to dangerous levels of mercury. These new measures will slash toxic mercury pollution from power plants by more than 90 percent and make breathing fresher air possible for millions of Americans. That's why the Sierra Club is airing this message of gratitude in Ohio, a state with the second highest rate of mercury pollution in the country.

"We want to ensure that women and families in Ohio understand what this new protection will mean for keeping their children and loved ones safe and healthy," said Michael Brune, executive director of the Sierra Club. "The Sierra Club applauds the President and EPA Administrator Lisa Jackson for their courage and resolve in protecting American families -- particularly women and children -- from this dangerous toxin and for standing up to polluters' attempts to weaken this life-saving protection."

The ad states:

When this little girl grows up her world will have significantly less mercury pollution because President Obama and the EPA stood up against polluters and established the first-ever clean air standards. This action means that our air, water, and food will be safer from mercury pollution and heavy metals generated by coal-fired power plants.

Like you, President Obama understands that reducing toxic mercury pollution increases the possibilities to dream big.

Well, we certainly are closing out this year with lots of good news to report. Today, the Sierra Club and Audubon are announcing a legal settlement with American Electric Power/Southwestern Electric Power Company (AEP/SWEPCO) that will retire a dirty coal plant and bring us lots of new clean energy. If all you wanted for Christmas this year was clean air, then you are in luck!

The deal will retire Welsh 2, a dirty coal plant upwind of Arkansas in northeastern Texas. It requires AEP to install 400 MW of clean energy – the equivalent of a medium-sized coal plant. It includes $2 million to support increased energy efficiency programs in Arkansas, Oklahoma, Louisiana, and Texas, which will help lower electric bills for families at a time when every penny counts. It prevents siting of transmission lines in sensitive natural areas. And it sets aside $8 million for land and habitat conservation in the region, which will go to the Nature Conservancy.

The settlement will also allow AEP to finish construction on the nearly-complete Turk power plant in Arkansas, which the Sierra Club and allies have been fighting for four years.

As Glen Hooks, our Sierra Club campaign representative in Arkansas, put it, "While we'd prefer that the Turk plant not be built, today's settlement brings some very good news for Arkansas, which would not have been possible without years of citizen opposition to dirty coal plants."

This settlement continues a trend that is underway nationwide – old, dirty coal plants are on their way out, and clean energy is on the rise. In 2011, we saw the largest-ever solar investments, and the second-largest investments ever in wind. Since January 2010, over 10% of the nation's coal plants have been slated for retirement. And since we launched our Beyond Coal campaign in 2002, we have defeated 161 new coal plants, leaving the door open for the clean energy revolution that is now taking center stage.

This holiday, I'm thankful for all the allies and activists that helped make this happen, including amazing legal work by the Environmental Integrity Project.

This AEP settlement is one more landmark victory along the way towards a clean energy future. Have a happy holiday season – here’s to making 2012 a banner year for clean air, clean water, and clean energy!

Three years ago this week, Americans saw one of the worst coal ash spills in Tennessee, when a billion gallons of toxic sludge poured onto farmland and into the Emory and Clinch rivers. In the disaster, Americans saw first-hand the consequences of delegating the job of handling coal ash to states, who lack the will and ability to protect communities. We thought it would be the final straw and that national safeguards to protect Americans from this hazardous material would surely follow.

Our nation's coal-fired power plants produce 140 million tons of coal ash every year, making it the second-largest industrial waste stream in the country. Across the country, millions of tons of coal ash are being stored in unlined ponds, landfills and mines. Many of these sites lack adequate safeguards, leaving nearby communities at risk from potential large scale disasters, like the massive coal ash spill in Tennessee in 2008, and from gradual yet equally dangerous contamination as coal ash toxins seep into drinking water sources. Despite its hazardous characteristics, coal ash is not subject to federal protections, and state laws governing coal ash disposal are usually weak or non-existent.

Coal ash, the by-product of burning coal, contains high levels of toxic heavy metals such as arsenic, cadmium, and hexavalent chromium. The public health and environmental hazards from unsafe coal ash dumping have been known for many years, including increased risk of cancer, learning disabilities, neurological disorders, birth defects, reproductive failure, asthma and other sickness.

But since the 2008 Tennessee disaster, the coal industry has lobbied hard to block the Environmental Protection Agency from establishing strong protections. The states, they say, are doing a fine job managing coal ash. In reality, the state laws governing disposal of coal ash are usually either weak or nonexistent.

Thankfully, there is hope. The Environmental Protection Agency has proposed safeguards for coal ash which would phase out these surface impoundment "wet dumps" - the most dangerous ash disposal method - and put in place common-sense safeguards that protect human health and the environment by governing the disposal and recycling of dry coal ash.

EPA has said they will finalize their standards in 2012, but until then, every day we wait for federal protections, another tragedy like the one on Tennessee could happen.

People rallying at the Philadelphia EPA mercury hearing. Photo by SHARON GEKOSKI-KIMMEL / Staff Photographer for the Philadelphia Inquirer

Are you one of the over 800,000 people who submitted a comment to the Environmental Protection Agency supporting proposed mercury pollution protections? Are you one of the hundreds who attended a public hearing in Chicago, Atlanta, or Philadelphia to support the draft standards? Are you one of the hundreds who attended a hair testing event to check your mercury levels, organized a stroller brigade with fellow parents, or joined a rally to get these protections across the finish line?

As I reflect on this remarkable achievement, I also find myself thinking about the day I learned I was pregnant with my daughter Hazel, who is now one-and-a-half. It was a miraculous feeling, knowing that I was bringing a baby into the world. I pledged to eat right, exercise, and take care of myself, so that I could give her the best possible start in life. I also hoped I hadn't eaten too much fish high in mercury in the months prior to getting pregnant, since I knew I would be passing all that mercury to my baby in the womb. Thankfully, my mercury levels were low and Hazel is a happy, healthy toddler.

With these new protections in place, moms and dads of the future may have one less thing to worry about. Women and young children will be protected by these new safeguards – a critical move because each and every year, more than 300,000 babies are born who have been exposed to dangerous levels of mercury in the womb. These protections against toxic mercury will slash mercury pollution by over 90 percent from every single coal plant in America, and will improve the lives of hundreds of thousands of women and young children.

This historic announcement comes after more than two years of amazing grassroots work to raise awareness about mercury pollution and show support for mercury protections. I think of all the people who held or participated in mercury hair testing events, got postcards signed, attended or organized around a hearing, held or attended any of the dozens of other mercury awareness events organized nationwide, or submitted one of the more than 800,000 supportive comments received by EPA – the largest number of comments ever submitted to EPA on any issue.

Congress required reductions of mercury and other air toxics from power plants way back in 1990, when they passed amendments to the Clean Air Act, but the coal industry had succeeded in blocking the standards for over two decades. Now, the wait is over, and these long-overdue protections are finally in place.

Here are Heather Hatzenbuhler from the Sierra Student Coalition and Toby Davine from Canada's Youth Climate Committee reacting to the COP17 climate conference. "The United States' lack of urgency and ambition in these negotiations is deplorable," Heather says.